Portable grinding device



F. G. P'iCK. PORTABLE GRINDING DEVICE.

1,340,120. APPLICATION FILED MAILZS. I919 May 11,

4 SHEETSSHEET Z F. G. PECK.

PORTABLE GRINDING DEVICE.

APPLICATION FILED MAR. 25. I919. 1,340,120. Patented y 11,1920.

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xrrarwzz F. G. PECK. PORTABLE GRINDING DEVICE.

1,340,120. APPLICATION FILED MAR. 15. IQIQ. ted May 11, 4 SHEETS-SHEET4- 7 llnlu FREDERICK GEORGE PECK, OF BRADFORD, PENNSYLVANIA, ASSIGNOR,BY MEBNE ASSIGNMENTS, TO JAMES H. MALONE, OF PHILADELPHIA, PENNSYLVANIA.

PORTABLE GRINDING DEVICE.

Specification of Letters Patent.

Application filed March 25, 1919. Serial No. 285,077.

To all whom it may comm-n Be it known thatl, FREDERICK G. PEGK, acitizen of Canada, residing at the city of Bradford, in the county ofMcKea-n and State of Pennsylvania, have invented a certain new anduseful Portable Grinding Device, of which the following is aspecification.

This invention relates generally stated to devices designed for cuttingscrew-threads, grinding and truing screw-threads, grinding cylindricalsurfaces and analogous purposes. The invention has more particularrelation to a portable grinding device which among other uses may beattached to the tool holding parts of a machine, as a lathe, wherein alladjustments capable of being imparted to a tool mounted upon aparticular machine, may. be imparted to such device.

The highest degree of accuracy is demanded of a device of this characterand practice has dictated the uncertaintyand impracticability of suchattachments for this purpose as are now upon the market. The chiefdifiiculty experienced has been that vibration from the driving means isreferred to the shaft or spindle carrying the grinding wheel or disk. Ithas been sought to eliminate, without commercial success. such vibrationby providing the shaft or spindle carrying the grinding wheel or diskwith an interlocking vibration absorbing connection of which one partcarries the driving pulley and of which the other part carries grindingwheel or disk.

I have discovered a practical and commercially successful way ofpreventing vibration from being referred to the shaft or spindlecarrying the grinding wheel or disk of a grinding device or attachmentand this may be said to constitute the leading object of the presentinvention.

Another difficulty experienced has been that when presenting a grindingwheel to work to be done there occurs momentarily unsuflicient or aslacking of belt-power. This is particularlytrue if a heavy cut is to beeffected. I have discovered that by employment of the vibrationpreventing means'above referred to, I am enabled to eliminate thisdis-advantageous feature and provide for automatically regulating thefrictional engagement of a belt with its driving pulley whichconstitutes another object of the present invention.

Other and further objects relate to the construction of the device orattachment as will hereinafter more fully appear.

\Vith these and still other objects in view, as will hereinafter appear,the invention consists of the improvements hereinafter described andfinally claimed.

The nature, characteristic features and sec e of the invention will bemore fully un erstood from the following description. taken inconnection with the accompanying drawings forming part hereof, and inwhich:

Figure 1, is a top or plan view of the grinding attachment.

Fig. 2, is a view in front elevation thereof.

Fig. 3, is a view in side elevation thereof.

Fig. 4, is a fragmentary view in elevation, principally sectioned,looking from the rear in Fig. 1.

Fig. 5, is a similar view in plan, principally sectioned, looking fromthe rear in Fi 2,

ig. 6, is a similar view in section of parts shown in Fig. 3, and

Fig. 7, is a view in side elevation of the grinding attachment providedwith a slightly diflerent form of tension transmismen.

For the purpose of illustrating my inven tion, I have shown in theaccompanying drawings forms thereof which are at present preferred byme, since the same have been found in practice to give satisfactoryandreliable results, although it is to be understood that the variousinstrumentalities of which my invention consists can be variouslyarranged and organized and that my Patented May 11. 1920.

' are provided the nut 17 so accuracy may be had when adjusting theblock 16. To clamp the block in adjusted position screws 19 areemployed. So mounted upon the front face of the block 16 as to becapable of being adjusted in an arc of a circle is a plate 20 the frontof which is mortised as at 21. To secure the proper adjustment of plate20, use is made of a stud having an annular bearing-face 22 and a pairof threaded extensions 23 and 24- ot reduced diameter. The part 22 isrotatably seated in block 16, the threaded extension 23 engaging atapped portion of the plate 20 and the threaded extension 24 beingengaged. by a nut for clamping the plate in fixed position against theblock 16 after proper adjust ment has been secured. The part 22 isprovided with a graduated disk 22 so accui.

racy may be had when adjusting the plate 20. Adjustable endwise throughthe mortised portion of the plate 20 is a member 25 provided with tenonsfor cooperatively engaging the said mortised plate. This memberterminates in a tubular portion 25' which may be termed a spindle husing which housing is cut away as at 26 to form a u shaped opening toaccommodate a grooved pulley 27 to be presently described. Rotatablypositioned with respect to the spindle housing is an adjusting screw 28,see Fig. 5, the threaded end of which engages the tapped portion 29 ofplate 20* whereby endwise adjustment of member 25 may be effected withrespect to plate 20. The screw 28 is provided with graduations 28 soaccuracy may be had when adjustin member 25. thrust bearings 30,supported in the spindle housing 25' is a spindle or shaft 31 to whichis removably secured the grooved pulley 27. and a grinding wheel or disk32. The spindle is provided with a screw-threaded extension 33 see Fig.'5, to receive an internally screw-threaded stem 34.- which in turnremovably supports, by means of a screw 35 in engagement with thescrew-threads of stem 34, the grindin Wheel or disk 32 which is made ofcarborun um. Such adjustments of the ball bearings with respect to thespindle as are necessary are made by means of disk 36 and 36' which havescrew-threaded relation with spindle housing 25' as clearly shown inFig. 5.

The means employed fordriving the spin- Rotatably mounted 1n en dle orshaft 31 comprises an electric motor 37 which is mounted directly uponthe spindle housing 25' and is operatively connected with respect to thegrooved pulley 27 by means of a tension transmission. As shown in Figs.2 and 3 the motor 37 is supported upon a standard 33 which is clamped asat 39 to the spindle housing. By such construction several motors may besupplied with the device so that interchangeable motors are providedfor. The motor-shaft 40 has removably secured thereto a grooved pulley41., the grooves being annular in character and three in number,practice having demonstrated that this number of grooves desirable. Thepulley 27 which is mounted upon the spindle or shaft 31 in similar inconstruction to pulley 41 except that it is provided with an additionalgroove, the pulley being made a little longer 5 for this purpose. Thepulleys are removable so that pulleys of varied diameter may besubstituted to obtain various speed ratios when desired. The pulleys 4-1and 27 which are of relatively small diameter, are so disposed that thegrooves of pulley 4]. are in alinement with three of the grooves ofpulley 27 and the horizontal axes of the motor-shaft and spindle 31 arein alinement. Pivoted as at 42 to a support 43 carried by the motorcasing is a substantially h0rizon tally disposed arm 44 under springtension, as at 45. As shown in Figs. 1, 2 and 3 this arm rotatablycarries at its free end a pulley 16 of relatively large diameter havinga single, annular groove. The horizontal axis of the pulley 46 is in aplane intersecting the plane of the axes of the motor shaft and spindle31 as is clearly shown in Fig. 1. (onnecting the three grooved pul leysis an endless belt 47 of which three runs of the belt are accommodatedby the grooved pulleys 27 and 40 and the fourth run of the belt isaccommodated by the pulley 46. However, I have discovered that, while asingle pulley of relatively large diameter is eflicient in the obtainingof proper belt tension, there are times when such a pulley is notpractical. This is par ticularly true when interchangeable motors areemployed. In such cases it becomes necessary at times, to employ uponthe motor shaft 40 a pulley of large diameter in order to secure aproper ratio of speed of the spindle 31. Frequently the motor pulley isof such diameter as to interfere with the pulley 46. Thus, for generaluse I prefer to employ the form of tension device shown in Fi 7. Rigidlyfixed to the forward end o arm 44 as at 44: is a horizontall disposedcross-piece 48. The crossiece 1s hor1zonta1ly slotted as at 49-50.ounted in said slots for adjustable movement toward or away from the arm4.4: are pulleys 51-52 of relatively small diameter. By

HIT:

this feature the pulleys may be properly positioned to accommodate abelt 47. Also a pulley 41 of relatively lair e diameter may be appliedto a motor sha t without int-erfering with the pulleys 51-52i y theabove described arrangements proper belt-tension is taken care ofautomatically so that spindle 31 is given sefficient belt-power at alltimes particularly when introducing the grinding wheel to Work and whenheavy cuts are to be efffected. Also perfect alinement of the *ulleyparts is insured at all times regar less of adjustments to securevarious spindle locations and a total absence of vibration upon thespindle or shaft 3i is noted since all vibration as would ordinarily bereferred to said spindle is taken 11 by the tension transmission. As topossi le spindle locations it will be understood that the spindlehousing, which carries the spindle and motor including the tensiontransmis sion ma be adjusted vertically, horizontally an in an arc of acircle. By the adjustment upon an arc of a circle the spindle end whichcarries the grinding. wheel or disk may be tilted above and below itsnormal, horizontal position.

t is sometimes desirable to practice upri ht surface grinding upon amilling machine having an overhead shaft. In such case the grindingdevice of the invention may be more readily and expeditiously clamped toplace upon the milling machine by providing the base 10 of the devicewith a longitudinally disposed V-shaped slot 10 upon its upper face.

Adapted for detachable connection to plate 20 is a disk-facing or truingdevice. This device comprises generally stated a tool support and anadjustable holder 54 or receiving a diamond By means of this device thegrinding wheel or disk 32 may be accurately dressed.

It will now be apparent that I have do vised a novel and usefulconstruction which embodies the features of advantage enumerated asdesirable in the statement of the invention and the above descriptionand while I have in the present instance shown and described thepreferred embodiment thereof which has been found in practice to givesatisfactory and reliable results, it is to be understood that the sameis susceptible of modification in various particulars without departingfrom the spirit or scope of the invention or sacrificing any of itsadvantages.

What I claim is 1. A device of the character stated comprising arotatable spindle provided with a grinding-wheel, a member in which saidspindle rotates, a motor supported by said members, groox'ed pulleysfixed to said spindle and to the shaft of said motor, a pivetailsupported arm under spring tension,

grinding-Wheel, a grooved pulley fined t6 said spindle,ameinber in whichsaid spindle rotates, a motor supported by said memher, a grooved pulleyfixed to the shaft of said motor, an arm under spring tension pivotallysupported upon said motor, at least one grooved pulley operativelycarried by said arm, the face of such pulley being in a plane parallelwith the said pivotal connection, an endless belt the runs of which passaround the said pulleys and means for adjustablv moving said member in adirection paralleling the axis of said spindle.

3. A device of the character stated comprising a rotatable spindleprovided with a grinding-wheel, a grooved pulley fixed to said spindle,a member in which said spindle rotates, a motor supported by saidmember, a grooved pulley fixed to the shaft of said motor, an arm underspring tension pivotally supported upon said. motor, at least onegrooved pulley operatively carried by said arm, the face of such pulleybeing in a plane parallel with the said pivotal connection, an endlessbolt the runs of which pass around the said pulleys, means foradjustably moving said member in a direction paralleling the axis ofsaid spindle and means for adjustably moving said member in a directionat right angles to the axis of said spindle.

4. A device of the character stated comprising a rotatable spindleprovided with a grinding-wheel, a grooved pulley fixed to said spindle,a member in which said spindle rotates, a motor supported by saidmemher, a grooved pulley fixed to the shaft of said motor, an arm underspring tension pivotally supported upon said motor, at least one groovedpulley operatively carried by said arm. the face of such pulley being ina plane parallel with the said pivotal connection, an endless bolt. theruns of which pass around the said pulleys, means for adjustably movingsaid member in a direction paralleling the axis of said spindle; meansfor :uljustably moving said member in a direction at right angles to theaxis of said spindle and means for adjustably oscillating said memberupon an axis at right angles to the axis of said spindle.

5. A device of the character stated comprising a rotatable spindleprovided with a grinding-Wheel. a grooved pulley fixed to said spindle,a member in which said spindle rotates, a motor supported by said memberwhich motor is provided with a shaft the axis of which parallels theaxis of the spindle, a grooved pulley fixed to said motor shaft, an armunder spring tension pivotally supported upon said motor, a cross-piecefixed to said arm, grooved pulleys journaled to said cross-piece and anendless belt passing around the respective pulleys.

6. A device of the character stated comprising a rotatable spindleprovided with a grinding wheel, a pulley having a plurality of groovesfixed to said spindle, a member in which said spindle rotates, a motorsupported by said member which motor is provided with a shaft the axisof which parallels the axis of the spindle, a pulley having a pluralityof grooves fixed to said shaft, an arm under spring tension pivotallysupported upon said motor, a crosspiece fixed to said arm, pulleys eachhaving a single groove journaled to said crosspiece and an endless beltthe runs of which first pass around the plurality of grooves of themotor shaft and spindle pulleys and thence around the single groove ofthe remaining pulleys.

7. A device of the character stat-ed comprising a rotatable spindleprovided with a grinding wheel, a grooved pulley fixed to said spindle,a member in which said spindle rotates, a motor supported by saidmemher, a grooved pulley fixed to the motor shaft, an arm under springtension, a crosspiece fixed to said arm, grooved pulleys ad justablymounted upon said cross-piece and an endless bolt the runs of which passaround the respective pulleys.

8. A device of the character stated comprising a rotatable spindleprovided with a grinding wheel, a grooved pulley fixed to said spindle,a member in which said spindle rotates, a motor supported by saidmember, a grooved pulley fixed to the motor shaft, an arm under springtension, a crosspiece fixed to said arm said cross-piece being slotted,grooved pulleys adjustably mounted in said slots and an endless belt theruns of which pass around the respective pulleys.

9. A device of the character stated comprising a rotatable spindleprovided with a grinding wheel, a grooved pulley fixed to said spindle,a member in which said spindle rotates, a motor supported by saidmember, a grooved pulley fixed to the motor shaft, an arm under springtension pivotally carried upon said motor, a horizontally disposed crosspiece fixed to the free end of said arm said cross piece being slotted,grooved pulleys journaled in said slots and adjustable toward or awayfrom said arm and an endless belt the runs of which pass around therespective pulleys.

10. A device of the character stated comprising a rotatable spindleprovided with a grinding wheel, a member in which said spindle rotates,a motor supported b said member, grooved pulleys fixed to sai spindleand to the shaft of said motor, a sup port mounted upon said motor,"anarm under spring tension, a grooved pulley carried by said arm, a pivotpin for securing said arm with respect to said support said pivot pinpassing through said arm in a plane parallel with the face of thegroovedpulley of said arm and'an endless belt the runs of which passaround said pulleys; 7

In testimony whereof, I have hereunto signed my name.

FREDERICK GEORGE P 13011.

